Automatic refusing mechanism



March 23, 1937. w. H. FRANK ET AL AUTOMATIC REFUSING MECHANISM Original Filed April 19, 1935 LOAD LIN E L TTORNE Y.

I March 23, 1937. w. H. FRANK ET AL 2,074,646

AUTOMATIC REFUSING MECHANISM Original Filed April 19, 1933 2 Sheets-Sheet 2 i W 165 a I60 3 E] 164 r '67 O 0 I63: Fr 6- I68 g l x 151 O O O 21/140 L 1 /1 I53 g M 56 155 m 4} 6 x \\\\\\\\\x\\\\ \\xx\ x x x g I INYENTORS ATTORNEY.

Patented Mar. 23, 1937 UNITED STATES PATENT OFFICE AUTOMATIC REFUSIN G MECHANISM Mich, a corporation of West Virginia Original application April 19, 1933, Serial No.

666,786, now Patent No.

1935. Divided and this 1935, Serial No. 4,606

6 Claims.

This application relates to circuit protective devices, and is a division of a prior application, Serial No. 666,786, filed April 19, 1933, now Patent Number 2,000,016, of May 7, 1935.

It is proposed by the present invention to combine with a multiple fuse wheel or body of the type disclosed in the aforesaid application a mechanism which automatically rotates the wheel upon the blowing of a fuse, so as to introduce a second fuse into the circuit, the device in this regard operating as an automatic refusing circuit protective device. The mechanism of the instant application is so constructed that a limited number of refusing operations occur automatically, two being the number chosen in the embodiment illustrated. The operation is such that when a fuse blows and opens the circuit, a second fuse will automatically be placed into the line to close the circuit once more; and when this second fuse blows, a third fuse will automatically be placed into the line; however, when the third fuse blows, the circuit will remain open and the device will no longer function automatically, but must be reset by the operator, who must perform this operation manually. Limiting the number of automatic re-fuse operations that can take Place before the operator is called upon to close the circuit and reset the device is desirable since it prevents all of the fuses being successively put into a circuit that happens to be continuously overloaded or contains a continuous short circuit.

In the embodiment of the invention illustrated there is provided a spring which is the motivating force in the matter of automatic re-fusing and the spring is so constructed that it is re-wound, after it has lost its original tension, each time the operator resets the device, i. e., after the third of the three fuses in a group has been blown.

A further object is the provision of a mechanism of the character described above which is so constructed that one handle serves as a spring-winding handle, and a handle for resetting the device, and further is equipped with a contact am so that it may serve as a switch handle for permitting manual switching operations.

A further object is the provision of a mechanism of the character described above, in combination with a multiple fuse wheel or body, which is so constructed that the mechanism, and the wheel or body, may be removed from the casing of the device as' a unit and replaced by another unit of the same character, when replacement is considered necessary.

A further object is the provision of a circuit 2,000,016, dated May 7, application February 2,

protective device including a thermal or warping element, the device being constructed to rupture the circuit automatically on overload, and to be moved to close the circuit automatically shortlythereafter, the means for moving the operating parts of the device being independent of the thermal element. In this respect, the instant application resembles the copending applications,

Serial Nos. 667,149-667,152, inclusive, filed April 21, 1933, on automatically resetting circuit breakers.

Still further objects of the present invention will presently appear upon reference to the following detailed description of an embodiment of the same disclosed in detail in the accompanying drawings. In these drawings,

Fig. 1 is a top plan view, with the cover removed, of an automatically re-fusing circuit protective device, employing a wheel such as has been previously disclosed in application Serial No. 666,786, now Patent No. 2,000,016, of May 7, 1935, as the multiple fuse element;

Figs. 2 and 3 are, respectively, elevational section and end section views of the same, as if on lines 2-2, 3-3 of Fig. 1, parts being cut away for purpose of clarity;

Fig. 4 is a view of a modified form of indexing arrangement capable of being used in the device of Figs. 1-3;

Fig. 5 is a view similar tothat of Fig. 2 but with the parts shown in a second position;

Fig. 6 isa partially cutaway elevational section of the device as if from the opposite side of the device from the view of Figs. 1-3, with the thermal element shown as warped due to an overload and just prior to its cooling or returning position.

The circuit protective device of this case employs as the operated element a wheel which may be of the construction shown in application Serial No. 666,786, now Patent No. 2,000,016, of May 7, 1935. The device includes a cup-shaped base 0 adapted to be closed by a cover I through whose slot I42 projects a manual switching arm I43, provided for purposes to be described later. The opposite wall of the base 0 and of the cover I are provided with semi-circular bosses II45 having registering semi-circular grooves which provide bearings for the ends oi. the operating shaft 6 of the device. It is observed that the cover I is completely detachable from the base and the contained parts merely by sliding it upwardly and over the end of the handle 1,43.

The operating shaft Mi supports the wheel W" which is provided with a number of fuses F, (twelve indicated), any one of which may be brought in station with and so as to connect the upstanding contacts ldl-Hlt, one of which, Hill, is connected by a lead M9 to the live side of the line through a second pair of contacts led adapted to be engaged by the bridging end of the switch arm. l5l, and the other of which is connected to the load side of the line by a lead it? and through a thermal bimetallic warping element I53. The interior of the wheel communicates with the interior of the shaft, which is hollow, in accordance with the principles disclosed in Fig. 1

of the aforesaid application, so that gases from 'the explosion chambers in the wheel may vent through the shaft to the atmosphere.

The arm l5I is rigidly connected to the manual switching arm M3 which in turn is provided with a pin E55 disposed in a slot H55 in a boss let projecting upward from the base, the pin ltd journalling the handle M3 so that the latter, when moved, can cause its arm lei to close the circuit through the contacts I50.

The fuse wheel W is rotatable on the shaft ldt and is connected to a ratchet wheel l60, in any suitable manner, as for example by a pin lfil projecting from the fuse wheel into the ratchet wheel whereby the two wheels rotate in unison on the shaft. For cooperation with such ratchet wheel there is provided a pawl l62 pivoted at its to a crank ltd keyed to the operating shaft I66, the pawl being biased towards the teeth of the ratchet by means of the pawl spring l65. The crank ltd has a lug IBM in line with handle M3 and adapted to engage the latter, as will be later mentioned. Fixed to the end of the operating shaft which projects through a slot I68 of the handle I63 is one end of a clock spring lt'l whose other end is hooked around a lug 58 of the base 0, and it will be observed that this spring con- 40 stantly tends to rotate the shaft counterclockwise,

Fig. 2.

Also rotatably mounted on the shaft, adjacent to that side of the wheel W opposite ratchet wheel I60 is an indexing plate Ill! having a num- 45 ber of pins IiI corresponding to the number of fuses on the wheel W, and this plate is connected to wheel W in any suitable manner, as for example by a pin i'I2 projecting from the fuse wheel into the index wheel, so as to rotate there with. Cooperating with this indexing plate is the bimetallic arm l53 connected in the load circuit so as to be responsive to conditions of the load, the bimetallic arm warping on overload and returning thereafter in cooling. The arm IE3 is 55 guidedby and connected to axle M6 by a link I80 whose slot I8I receives the axle, and this link, pivoted at I82 to the arm l53, contains a pair of stops ll3-I'I4.

The operation of the device is as follows: Assume the parts to be in the position of Fig. 2, with the circuit closed from line contact I50, through switch arm I5I, and the other line con: tact I50, then through flexible lead M9 to contact I41, then through the fuse F in station to the contact M8, then through flexible lead I52 to one of the binding posts at the base of the warping arm I53, then through the warping arm to the other binding post and to the load.

When an overload occurs the fuse F which 7Q happens to be in station with contacts IMI48 will of course blow. This ruptures the circuit, after the fuse has attained suflicient temperature to blow. During the heating of the fuse the warping element I53 alsoibecomes heated by the over- 75 load condition and is so calibrated that it warps to such a position (Fig. 6) that its 'stop lid becomes disengaged from the pin llI resting thereon. The spring it? therefore rotates the shaft and the indexing plate H0 counterclockwise (Fig. 2), clockwise, Figs. 4 and 6. Rotation of the shaft causes rotation of the crank ltl'l counterclockwise and pawl W3 picks up ratchet ltd to move it one station. Such rotation of the ratchet wheel is accompanied by rotation of the fuse wheel W and accordingly another fuse is presented in station with contacts lei-4&8, to close the circuit once more.

Pin ill of the indexing plate, which had been in engagement with the stop El i, now engages stop lit which moves into the path of the pins lll during the time that arm use warps on overload. Engagement of pin ill by stop I13 therefore prevents the furthermovement of the parts at this time. This engagement stops all movement of the parts and indexes the parts so that alignment of a fuse properly with respect to contacts lillll8 is assured.

When the thermal element I53 cools, after its momentary warping, stop 3 moves out of the path of pin ill and the indexing wheel is free to rotate in concord with rotation of the crank I66, but only until the next adjacent pin lll engages stop l'ld, which returns into the path of pins ill on cooling of the element I53.

If the overloadis still on the line, or if after an interval of proper load condition of the line, an overload again occurs on the line, the above mentioned cycle of operations will take place once again. However, when the second cycle of operations terminates it will be found that stop I651; of crank i6 5 is in engagement with the handle M3. This prevents further movement of the parts until the handle M3 is manipulated. That is to say, this places the parts in closed circuit position after two fuses have been blown, ready for another fuse blowing on overload, but looks the parts so that upon this last mentioned, or third fuse blowing, there will be no automatic re-fusing until the handle I43 is manipulated. Therefore the device will be found to provide three overload circuit ruptures with the last one leaving the circuit open until the operator manipulates the handle I43.

When he does this, hefirst opens the already open circuit, by causing the switch arm ltl to leave contacts I50. Movement of the handle M3 to the right from the position of Fig. 2 moves the crank IN back to the original position (Fig. 2) and rewinds the spring I61. This is a resetting operation which places the parts in position to go through three circuit ruptures andtwo automatic re-fusings with the last circuit rupture not accompanied by automatic re-fusing. The resetting. operation is not accompanied by movement of ratchet I60, wheel W, or plate I10.

The mechanism above described can very well be called a limited cycle automatic re-fusing circuit protective device, the limited cycle description being appropriate because of the fact that the cycle of automatic re-fusing is not continuous but terminates after three circuit ruptures and two automatic re-fusings. In this respect the instant application resembles the copending application Serial No. 667,152, filed April 21, 1933,

relating to a limited cycle automatically resetting circuit breaker. In Fig. 4 there is showna modification wherein the indexing stops ll3-I'I4 are formed direct y on the arm I53.

It will be observed that the entire mechanism aoraece on the shaft MS can be removed as a unit from v the base and replaced, so that after all of the Cal fuses on the wheel W have been blown, an electrician can. be called in by the inexperienced householder to replace the used wheel W? by a fresh wheel. This the electrician does by sliding the indexing plate off, sliding the used wheel oil the shaft M5, replacing the same by a fresh wheel, and returning the old indexing plate.

Now having described the device illustrated in the drawings, reference will be had to the follow= ing claims for a determination of the scope of the invention.

We claim:

'1. In a multiple fuse device, a body having fuses thereon, means for moving the body for refusing the circuit, as fuses blow, means for limiting the number of refusing operations of the first mentioned means, and reset means manually operable to render the limiting means inoperable and restore the operability of the refusing means.

2. In a multiple fuse circuit protective device, automatically operating means cyclically tending to rupture the protected circuit on the blowing of a fuse and then to establish the circuit through another fuse, a circuit responsive element controlling movement of said means in cycles and operating to hold said means in circuit established position or to release said means so that the same may rupture the protected circuit.

3. In a multiple fuse circuit protective device, automatically operating means cyclically tending to rupture the protected circuit on the blow ing of a fuse and then to establish the circuit through another fuse, a circuit responsive element controlling movement of said means in cycles and operating to hold said means in circuit established position or to release said means so that the same may rupture the protected circuit, the means, though controlled by the element, operating without the aid of the element.

4. In a circuit protective device, circuit closing means, a spring motor so connected to said circuit closing means as to cause the latter to open and close the circuit cyclically and automatically, means for limiting the number of cycles of operation of the motor and for inhibiting the motor against further operation when the parts of the device have come to rest in circuit open position after the limited number of cycles of operation have taken place, and manually operable means operable to close the circuit and rewind the spring of the motor.

5. In a circuit protective device, circuit closing means, a spring motor so connected to said circuit closing means as to cause the latter to open and close the circuit cyclically and automatically, means for limiting the number of cycles of operation of the motor and for inhibiting the motor against further operation when the parts of the device have come to rest in circuit open position after the limited number of cycles of operation have taken place, and manually operable means operable to close the circuit and rewind the spring of the motor and also operable for manual switching.

6. In a multiple fuse protective device, a multiple fuse element, a motor driven automatically operating fuse renewing mechanism therefor, including a motor detachably connected to the element, the element being readily separable from the mechanism as a whole so as to be replaceable without disturbing the motor of the mechanism.

WIILIAM H. FRANK. JOSWH A. MESSING. HARRISON J. L. FRANK. 

